Optical folding element, camera module, and electronic device

Abstract

The present application provides an optical folding element, a camera module, and an electronic device. The optical folding element comprises a first surface and a second surface which are arranged opposite to each other, wherein the first surface comprises an incident surface and an exit surface; the optical folding element further comprises a plurality of grooves; openings of the plurality of grooves are all formed on the second surface; and groove surfaces of the grooves can be used for reflecting light. First light enters the optical folding element from the incident surface, is reflected for multiple times in the optical folding element, and then is emitted out from the exit surface; and second light enters the optical folding element from the incident surface and is reflected in toward the incident surface under the action of the groove surfaces of the grooves. The optical folding element of the present application can effectively reduce the effect of stray light, thereby achieving good imaging quality.

Description

Optical folding element, camera module and electronic device

[0001] The present application claims priority to the Chinese patent application No. 202411373483.X, filed on September 29, 2024, entitled "Optical folding element, camera module and electronic device", the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the technical field of photographing devices, and in particular to an optical folding element, a camera module and an electronic device. BACKGROUND

[0003] When a user is photographing, in addition to the effective light in the photographing area entering the camera module, stray light outside the photographing area also enters the camera module and is imaged on the image sensor, reducing the imaging quality. In current camera modules for implementing long-focus photography, a prism is usually arranged to fold the light path, so as to increase the total length of the optical system of the module and meet the long-focus requirement. However, due to the presence of the prism, the interference of stray light in the long-focus camera module is very obvious, greatly affecting the imaging quality of photography.

[0004] SUMMARY

[0005] The present application provides an optical folding element with good imaging quality, a camera module including the optical folding element, and an electronic device including the camera module.

[0006] In a first aspect, an optical folding element is provided. The optical folding element includes a first surface and a second surface arranged opposite to each other, the first surface includes an incident surface and an exit surface, and the optical folding element further includes a plurality of grooves, openings of the plurality of grooves are formed on the second surface, and groove surfaces of the grooves are capable of reflecting light. Wherein, a first light enters the optical folding element from the incident surface, is reflected multiple times inside the optical folding element, and exits from the exit surface, and a second light enters the optical folding element from the incident surface and is reflected in a direction towards the incident surface under the action of the groove surfaces of the grooves.

[0007] It can be understood that when the user is shooting, the light of the external environment can pass through the lens and enter the inside of the optical folding element through the incident surface of the optical folding element. Among them, the light entering the camera module can include first light and second light. The first light can be effective light in the shooting area. The second light can be stray light outside the shooting area. In general, the camera module will usually set a blocking structure (for example, a groove is opened on the bottom surface of the optical folding element, and light-blocking ink is coated on the groove wall to block light) on the path of the stray light propagation inside the optical folding element to block the stray light, thereby reducing the influence of the stray light on the imaging quality. However, in order to avoid the influence of the blocking structure on the effective light imaging, the height of the blocking structure is limited, resulting in that part of the stray light enters the inside of the optical folding element through the lens and is not blocked by the blocking structure, and finally images on the image sensor, affecting the imaging quality.

[0008] However, in order to avoid the influence of the blocking structure on the effective light imaging, the height of the blocking structure is limited, resulting in that part of the stray light enters the inside of the optical folding element through the lens and is not blocked by the blocking structure, and finally images on the image sensor, affecting the imaging quality.

[0009] In a possible implementation, the incident surface and the exit surface are arranged in a first direction, and the plurality of grooves are arranged in the first direction. In this way, the plurality of grooves are arranged in the first direction, so that the grooves can better reflect the stray light toward the second surface in the direction toward the incident surface, effectively reducing the influence of the stray light on the imaging quality.

[0010] In a possible implementation, the groove is in a strip shape, and the length extension direction of the groove is parallel to the width extension direction of the optical folding element. In this way, the groove can better reflect the stray light toward the second surface in the direction toward the incident surface, effectively reducing the influence of the stray light on the imaging quality.

[0011] In a possible implementation, the groove surface includes oppositely arranged first and second groove surfaces, and the first groove surface is arranged at an angle with the second groove surface. In this way, the cross section of the groove can be approximately triangular, and the stray light toward the second surface can be reflected in the direction toward the incident surface under the action of the first groove surface and / or the second groove surface, thereby effectively reducing the influence of the stray light on the imaging quality and facilitating improvement of the user shooting experience.

[0012] In a possible implementation, the first groove surface and the second groove surface form a first included angle, and an angle of the first included angle is in a range from 60 degrees to 120 degrees, or an angle of the first included angle is in a range from 80 degrees to 100 degrees. In this way, the angle of the included angle between the first groove surface and the second groove surface is appropriate, the stray light can be better reflected, the stray light can be avoided from being imaged on the image sensor, the imaging quality can be improved, and the user experience is improved.

[0013] In a possible implementation, a width of the first groove surface is greater than or equal to 10 microns, and / or a width of the second groove surface is greater than or equal to 10 microns. In this way, the first groove surface and / or the second groove surface has a certain width, which can avoid excessive mechanical stress on one hand, and on the other hand, the face type of the groove is easy to guarantee during processing, and the processing precision is high.

[0014] In a possible implementation, the width of the first groove surface is equal to the width of the second groove surface. In this way, the triangle in which the first groove surface and the second groove surface are located can be approximately an isosceles triangle. When the stray light is incident on the first groove surface or the second groove surface, the stray light can be reflected once and propagate in a direction towards the incident surface, or the stray light can propagate in the direction towards the incident surface after being reflected multiple times between the first groove surface and the second groove surface, so that the stray light can be effectively prevented from being emitted from the exit surface to avoid imaging of the stray light on the image sensor, and the imaging quality is improved.

[0015] In a possible implementation, the first groove surface is connected to the second groove surface, or a connecting portion of the first groove surface and the second groove surface forms a fillet, and a radius of the fillet is less than or equal to 10% of a height of a triangle in which the first groove surface and the second groove surface are located. In this way, the cross section of the groove can be approximately a triangle, the stray light incident on the second surface can be better reflected in a direction towards the incident surface, and the imaging quality is improved.

[0016] In a possible implementation, a distance between two adjacent grooves is less than or equal to 10% of the height of the triangle in which the first groove surface and the second groove surface are located. In this way, the distance between the two adjacent grooves is close, so that the stray light incident on the second surface can be more reflected by the groove surfaces, the influence of the stray light on the imaging quality is reduced, and the user experience is improved.

[0017] In a possible implementation, the optical folding element further includes an optical absorption layer, the optical absorption layer is fixed in the groove, and covers at least part of the groove surface. In this way, when the stray light is reflected by the groove surface, part of the energy of the stray light can also be absorbed by the optical absorption layer, so that the stray light incident into the optical folding element can be better eliminated, the influence of the stray light is reduced, and the imaging quality is improved.

[0018] In a possible implementation manner, the optical folding element further includes a first reflecting surface and a second reflecting surface, the first reflecting surface and the second reflecting surface are located between the first surface and the second surface, the first reflecting surface and the second reflecting surface are arranged at an angle, and a distance between the first reflecting surface and the second reflecting surface decreases in a direction towards the second surface. In this way, after the first light enters the inside of the optical folding element, the first light can be reflected multiple times under the action of multiple reflecting surfaces until the first light is emitted by the exit surface, so that the optical path can be effectively folded, the focal length is prolonged, and the total length of the optical system is increased, thereby realizing miniaturization while obtaining a larger focal length.

[0019] In a possible implementation manner, the optical folding element further includes a light blocking layer, the light blocking layer is located between the first reflecting surface and the second reflecting surface, the light blocking layer is fixedly connected to the second surface and is arranged at a distance from the first surface, and a light passing region is formed between the light blocking layer and the first surface. In this way, the effective light can pass through the light passing region and is finally emitted by the exit surface, a part of the stray light can be intercepted by the light blocking layer, and a part of the stray light can be reflected by the groove surface. That is, the light blocking layer can cooperate with the groove to jointly eliminate the stray light entering the inside of the optical folding element and reduce the influence of the stray light on the imaging quality.

[0020] In a second aspect, a camera module is provided. The camera module includes a lens, an image sensor, and the optical folding element described above, the lens and the image sensor are located on a side of the first surface of the optical folding element away from the second surface, the lens is arranged opposite to the entrance surface, and the image sensor is arranged opposite to the exit surface.

[0021] It can be understood that, in the camera module in this embodiment, a plurality of grooves are arranged on the bottom surface (that is, the second surface in this embodiment) of the optical folding element, and the groove surface can reflect the light. In this way, when the stray light enters the inside of the optical folding element through the lens, the stray light can be reflected by the groove surface and transmitted in a direction towards the entrance surface. That is, the stray light reflected by the groove surface will not be finally emitted by the exit surface and imaged on the image sensor, thereby effectively reducing the influence of the stray light on the imaging quality and facilitating improvement of the user's shooting experience.

[0022] In a third aspect, an electronic device is provided. The electronic device includes an image processor and the camera module described above, the image processor is in communication connection with the camera module, and the image processor is configured to acquire image data from the camera module and process the image data. The electronic device in this embodiment has good imaging quality when shooting. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the background art, the drawings required to be used in the embodiments of the present application or the background art will be described below.

[0024] FIG. 1 is a schematic structural diagram of an electronic device according to an embodiment of the present application;

[0025] FIG. 2 is a schematic partial cross-sectional structural diagram of the electronic device shown in FIG. 1 according to an embodiment;

[0026] FIG. 3 is a schematic structural diagram of a camera module according to an embodiment of the present application;

[0027] FIG. 4 is an exploded schematic structural diagram of the camera module shown in FIG. 3;

[0028] FIG. 5 is a schematic partial cross-sectional structural diagram of the camera module shown in FIG. 3 according to an embodiment;

[0029] FIG. 6 is a schematic diagram of light propagation when a camera module is shooting;

[0030] FIG. 7 is a schematic structural diagram of an optical folding element according to an embodiment of the present application;

[0031] FIG. 8 is a schematic structural diagram of the optical folding element shown in FIG. 7 from another perspective;

[0032] FIG. 9 is a schematic structural diagram of the optical folding element shown in FIG. 7 from yet another perspective;

[0033] FIG. 10 is a schematic diagram of light transmission of the camera module shown in FIG. 5;

[0034] FIG. 11 is a schematic structural diagram of the optical folding element shown in FIG. 7 according to another embodiment;

[0035] FIG. 12 is a schematic partial cross-sectional structural diagram of the optical folding element shown in FIG. 7 according to an embodiment;

[0036] FIG. 13 is a schematic cross-sectional simplified diagram of the groove shown in FIG. 12 according to another embodiment;

[0037] FIG. 14 is a schematic cross-sectional simplified diagram of the groove shown in FIG. 12 according to yet another embodiment;

[0038] FIG. 15 is a schematic cross-sectional simplified diagram of the groove shown in FIG. 12 according to still another embodiment;

[0039] FIG. 16 is a schematic diagram of a manufacturing process of the optical folding element shown in FIG. 7 according to an embodiment;

[0040] FIG. 17 is a schematic diagram of a manufacturing process of the optical folding element shown in FIG. 7 according to another embodiment. DETAILED DESCRIPTION

[0041] The embodiments of the present application will be described below with reference to the accompanying drawings.

[0042] In the description of the embodiments of the present application, it should be noted that unless specifically defined and limited otherwise, the terms "mount", "connect" should be interpreted broadly, for example, "connect" can be detachable connection, or can be non-detachable connection, can be direct connection, or indirect connection through intermediate medium. Among them, "fixed connection" refers to the relative position relationship after being connected with each other does not change. The orientation language mentioned in the embodiments of the present application, such as "upper", "lower", "inner", "outer" and the like, is only the direction of the reference drawing, therefore, the orientation language used is for better and clearer description and understanding of the embodiments of the present application, and is not intended to indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore, it cannot be understood as a limitation on the embodiments of the present application. "Multiple" means at least two.

[0043] In the embodiments of the present application, the terms "first", "second", "third", "fourth" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second", "third", "fourth" can explicitly or implicitly include one or more of the features.

[0044] In the embodiments of the present application, "and / or" is only a description of the association relationship between the associated objects, which means that there can be three kinds of relationships, for example, A and / or B can mean that there are three cases of A alone, A and B together, and B alone. In addition, the character " / " in this paper generally represents that the front and rear associated objects are a "or" relationship.

[0045] In this specification, the reference "one embodiment" or "some embodiments" and the like means that the specific features, structures or characteristics described in connection with the embodiment are included in one or more embodiments of the present application. Therefore, the statements "in an embodiment", "in some embodiments", "in other embodiments", "in another embodiment" and the like appearing in various places in the specification are not necessarily all referring to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized. The terms "include", "contain", "have" and their variants mean "including but not limited to", unless otherwise specifically emphasized.

[0046] Fig. 1 is a structural schematic diagram of an electronic device 1000 provided by an embodiment of the present application. Fig. 2 is a partial cross-sectional structural schematic diagram of the electronic device 1000 shown in Fig. 1 along A-A in an embodiment.

[0047] As shown in FIGS. 1 and 2, the electronic device 1000 can be a device having a camera module, such as a mobile phone, a tablet personal computer, a laptop computer, a personal digital assistant (PDA), a camera, a personal computer, a notebook computer, a vehicle-mounted device, a wearable device, augmented reality (AR) glasses, AR helmet, virtual reality (VR) glasses, or VR helmet. The electronic device 1000 of the embodiment shown in FIG. 1 is described by way of example of a mobile phone.

[0048] As shown in FIGS. 1 and 2, the electronic device 1000 can include a camera module 100, a device housing 200, a screen 300, and an image processor (not shown). The camera module 100 can be a rear camera module or a front camera module. It should be noted that FIG. 1 and the relevant drawings hereinafter only schematically show some components included in the electronic device 1000, and the actual shape, actual size, actual position, and actual structure of these components are not limited by FIG. 1 and the drawings hereinafter. In addition, when the electronic device 1000 is some other form of device, the electronic device 1000 can also not include the screen 300.

[0049] For ease of description, the width direction of the electronic device 1000 is defined as the X-axis. The length direction of the electronic device 1000 is defined as the Y-axis. The thickness direction of the electronic device 1000 is defined as the Z-axis. It can be understood that the coordinate system of the electronic device 1000 can be flexibly set according to actual needs.

[0050] By way of example, the device housing 200 can include a frame 201 and a back cover 202. The back cover 202 is fixed to the frame 201. By way of example, the back cover 202 can be fixedly connected to the frame 201 by adhesive. The back cover 202 can also be an integral structure with the frame 201, i.e., the back cover 202 and the frame 201 are an integral structure.

[0051] In addition, the screen 300 can be located on the side of the frame 201 away from the back cover 202. At this time, the screen 300 and the back cover 202 are located on the two sides of the frame 201, respectively. The screen 300, the frame 201, and the back cover 202 collectively enclose the inside of the electronic device 1000. The inside of the electronic device 1000 can be used to place devices of the electronic device 1000, such as a battery, a receiver, or a microphone. The screen 300 can be a flat screen or a curved screen.

[0052] Exemplarily, the camera module 100 can be located inside the electronic device 1000. The camera module 100 can be fixed to a side of the screen 300 facing the back cover 202. The back cover 202 can be provided with a light transmission hole 203. The shape of the light transmission hole 203 is not limited to the circular shape shown in FIG. 1. The light transmission hole 203 connects the inside of the electronic device 1000 to the outside of the electronic device 1000. Light outside the electronic device 1000 can enter the inside of the electronic device 1000 through the light transmission hole 203. The camera module 100 can collect ambient light entering the inside of the electronic device 1000. Exemplarily, the camera module 100 can be a periscope camera module. The camera module 100 can be used for long-focus shooting.

[0053] Exemplarily, the image processor can be in communication connection with the camera module 100. The image processor can be used to obtain image data from the camera module 100 and process the image data. The communication connection between the camera module 100 and the image processor can include data transmission through electrical connection such as wiring, or can be achieved through coupling and other means. It can be understood that the camera module 100 and the image processor can also be in communication connection through other means capable of achieving data transmission.

[0054] The function of the image processor is to optimize the digital image signal through a series of complex mathematical algorithm operations, and finally transmit the processed signal to the display. The image processor can be an image processing chip or a digital signal processing chip.

[0055] It can be understood that the installation position of the camera module 100 in the electronic device 1000 of the embodiment shown in FIG. 1 is only illustrative, and the application does not strictly limit the installation position of the camera module 100. In some embodiments, the camera module 100 can also be installed at other positions of the electronic device 1000, for example, the camera module 100 can also be installed at the middle upper part or the right upper corner of the back of the electronic device 1000. In other embodiments, the electronic device 1000 can include a device body and an auxiliary component that can rotate, move or detach relative to the device body. At this time, the camera module 100 can also be provided on the auxiliary component.

[0056] FIG. 3 is a structural schematic diagram of the camera module 100 in some embodiments of FIG. 1. FIG. 4 is an exploded structural schematic diagram of the camera module 100 shown in FIG. 3. FIG. 5 is a partial cross-sectional structural schematic diagram of the camera module 100 along B-B in one embodiment of FIG. 3.

[0057] As shown in FIGS. 3-5, the camera module 100 can include a motor 10, a lens 20, an optical folding element 30, a bracket 40, an image sensor 50, and a circuit assembly 60. The image sensor 50 can also be referred to as a photosensitive chip or a photosensitive element. The image sensor 50 can be configured to collect ambient light and convert image information carried by the ambient light into an electrical signal.

[0058] Exemplarily, the optical folding element 30 can be fixed to the inner side of the bracket 40. The motor 10 and the image sensor 50 can be located on the same side of the optical folding element 30 and can both be fixedly connected to the bracket 40. The lens 20 can be mounted to the inner side of the motor 10. The motor 10 can drive the lens 20 to move in a direction close to or away from the prism to achieve optical focusing. In some embodiments, the motor 10 can also have an optical anti-shake function. That is, the motor 10 can be an integrated motor that takes into account both optical anti-shake and focusing functions.

[0059] Exemplarily, the motor 10 can be electrically connected to the image sensor 50 through the circuit assembly 60. In some embodiments, the circuit assembly 60 can also include a connector (not shown), such as a board-to-board connector. The circuit assembly 60 can be electrically connected to the main board (not shown) of the electronic device 1000 through the connector.

[0060] Exemplarily, light can enter the optical folding element 30 through the lens 20 and undergo multiple reflections inside the optical folding element 30, and then exit the optical folding element 30 to finally form an image on the image sensor 50. In this way, the light can undergo multiple reflections inside the optical folding element 30 before forming an image on the image sensor 50, thereby folding the optical path and effectively increasing the focal length and the total track length (TTL) of the camera module 100.

[0061] FIG. 6 is a schematic diagram of light propagation when a general camera module 400 is shooting. In FIG. 6, (a) and (b) are schematic diagrams of light entering the prism 410 at different angles.

[0062] As shown in FIG. 6, it can be understood that when the user is taking a picture, there is usually light (i.e. stray light) outside the shooting area that passes through the lens and finally images on the image sensor, affecting the imaging quality. In a general camera module 400, a blocking structure 420 is usually arranged on the path of the internal stray light of the prism 410 (for example, a slot is opened on the bottom surface of the prism 410, and light-blocking ink is coated on the slot wall to block light), to intercept and block stray light, thereby reducing the influence of stray light on imaging quality. However, in order to avoid the blocking structure 420 affecting the imaging of the effective light, the height of the blocking structure 420 is limited, resulting in that part of the stray light that enters the inside of the prism 410 through the lens 440 is not blocked by the blocking structure 420, and finally images on the image sensor 430, affecting the imaging quality. However, the camera module 100 in the embodiment can effectively eliminate stray light without affecting the imaging of effective light, and the imaging quality is high.

[0063] The optical folding element 30 will be described in detail below in conjunction with the relevant drawings.

[0064] FIG. 7 is a schematic structural view of the optical folding element 30 shown in FIG. 4 in some embodiments. FIG. 8 is a schematic structural view of the optical folding element 30 shown in FIG. 7 from another perspective. FIG. 9 is a schematic structural view of the optical folding element 30 shown in FIG. 7 from still another perspective.

[0065] As shown in FIGS. 7-9, the optical folding element 30 can be a prism. The optical folding element 30 can include a first surface 31 and a second surface 32 arranged opposite to each other. The first surface 31 can be parallel to the second surface 32 and arranged in the height direction (i.e. the Z-axis direction in the embodiment) of the optical folding element 30 with the second surface 32. The first surface 31 can be arranged closer to the lens 20 than the second surface 32. At this time, the first surface 31 can constitute the top surface of the optical folding element 30. The second surface 32 can constitute the bottom surface of the optical folding element 30. For example, in the length direction (i.e. the X-axis direction in the embodiment) of the optical folding element 30, the size of the first surface 31 can be greater than the size of the second surface 32.

[0066] For example, the optical folding element 30 can further include a first side surface 33, a second side surface 34, a third side surface 35, and a fourth side surface 36. The first side surface 33 can be arranged opposite to the second side surface 34. The third side surface 35 can be arranged opposite to the fourth side surface 36. The first side surface 33, the third side surface 35, the second side surface 34, and the fourth side surface 36 can be sequentially connected end to end. The first side surface 33, the second side surface 34, the third side surface 35, and the fourth side surface 36 can be connected between the first surface 31 and the second surface 32. The first side surface 33 and the second side surface 34 can be arranged in the length direction (i.e. the X-axis direction in the embodiment) of the optical folding element 30.

[0067] For example, the optical folding element 30 can have an entrance surface 30a and an exit surface 30b. The entrance surface 30a and the exit surface 30b can be formed on the first surface 31 of the optical folding element 30. That is, the first surface 31 can include the entrance surface 30a and the exit surface 30b. The entrance surface 30a and the exit surface 30b can be located on the same side of the optical folding element 30. The entrance surface 30a and the exit surface 30b can be arranged in the first direction. The first direction X can be parallel to the X-axis direction, i.e., the length extension direction of the optical folding element 30. After the light enters the interior of the optical folding element 30 from the entrance surface 30a, the light can be reflected multiple times in the interior of the optical folding element 30 and finally exit from the exit surface 30b. In other words, the entrance surface 30a and the exit surface 30b can be transmission surfaces for the transmission of optical signals in the optical folding element 30. The reflection of the light in the interior of the optical folding element 30 can be ordinary reflection or total reflection. For example, when the incident angle of the light is close to or greater than the critical angle of the optical folding element 30, the light can be totally reflected (TIR) in the interior of the optical folding element 30. It should be noted that the entrance surface 30a and the exit surface 30b are schematically shown by dashed lines in FIG. 7 and subsequent figures.

[0068] For example, the optical folding element 30 can include at least two reflection surfaces. The reflection surfaces can be formed by providing a reflective material on the surface of the optical folding element 30 (for example, by coating a reflective coating / pasting a reflective film, etc.). In this embodiment, the number of reflection surfaces can be three, for example, including a first reflection surface 371, a second reflection surface 372, and a third reflection surface 373. The first reflection surface 371 can be formed on the first side surface 33. The second reflection surface 372 can be formed on the second side surface 34. The third reflection surface 373 can be formed on the first surface 31 and located between the entrance surface 30a and the exit surface 30b. At this time, the first reflection surface 371 and the second reflection surface 372 can be located on the image side of the entrance surface 30a. The third reflection surface 373 and the entrance surface 30a can be located on the same side of the optical folding element 30.

[0069] For example, the first side surface 33 can be provided with reflective material throughout to form the first reflection surface 371. That is, the first reflection surface 371 can completely overlap the first side surface 33. The second side surface 34 can also be provided with reflective material throughout to form the second reflection surface 372. That is, the second reflection surface 372 can completely overlap the second side surface 34. In other embodiments, the first side surface 33 can also be provided with reflective material only in a partial region (for example, the central region of the first side surface 33) to form the first reflection surface 371. At this time, the part of the first side surface 33 that does not overlap the first reflection surface 371 can also be provided with light-absorbing ink to absorb stray light and improve imaging quality.

[0070] As shown in FIGS. 7-9, the first reflective surface 371 can form an included angle with the entrance surface 30a (i.e., the first surface 31 can form an included angle with the first side surface 33) less than 90°. The projection of the first reflective surface 371 on the plane where the first surface 31 lies can overlap at least part of the entrance surface 30a. The projection of the second reflective surface 372 on the plane where the first surface 31 lies can overlap at least part of the exit surface 30b. In this way, after the light rays enter the interior of the optical folding element 30 from the entrance surface 30a, the light rays can be reflected by one or more of the first reflective surface 371, the second reflective surface 372, and the third reflective surface 373, and finally imaged on the image sensor 50.

[0071] Exemplarily, the optical folding element 30 can further include a light blocking layer 38. The light blocking layer 38 can be located between the first side surface 33 and the second side surface 34, i.e., between the first reflective surface 371 and the second reflective surface 372. The light blocking layer 38 can be connected to the second surface 32 and spaced apart from the first surface 31. The light blocking layer 38 and the first surface 31 can form a light passing region 30c (shown in FIG. 5) for the light rays to pass through. In this way, by providing the light blocking layer 38 in the interior of the optical folding element 30 to block the light rays, the stray light outside the light passing region 30c can be prevented from passing through and being imaged on the image sensor 50, thereby affecting the imaging quality.

[0072] In some embodiments, the optical folding element 30 can further have a light blocking groove 381. The opening of the light blocking groove 381 can be formed on the second surface 32, the third side surface 35, and the fourth side surface 36. At this time, the light blocking groove 381 can be recessed into the interior of the optical folding element 30. The groove wall of the light blocking groove 381 can be subjected to light blocking treatment to form the light blocking layer 38. For example, the light blocking layer 38 can be formed by coating / pasting a light blocking material on the groove wall of the light blocking groove 381. In other embodiments, the optical folding element 30 can also be a glued prism. At this time, the optical folding element 30 can include a first sub-portion (not shown) and a second sub-portion (not shown) independent of each other. The first sub-portion can be fixed to the second sub-portion by gluing. In this way, the light blocking layer 38 can be formed by coating / pasting a light blocking material on the gluing surface of the first sub-portion and / or the second sub-portion. In some other embodiments, the optical folding element 30 can also not have the light blocking layer 38.

[0073] Referring to FIGS. 7-9 again, the optical folding element 30 can have a plurality of grooves 39. The plurality of grooves 39 can each be formed on the second surface 32. The plurality of grooves 39 can be arranged along the first direction X. The plurality of grooves 39 can each have the same shape and size. For example, the grooves 39 can each have an elongated shape. The length of the grooves 39 can extend parallel to the width of the optical folding element 30 (i.e., the Y-axis direction in the present embodiment). The plurality of grooves 39 can be uniformly distributed on the second surface 32. In other embodiments, the plurality of grooves 39 can each have different shapes and / or sizes.

[0074] For example, the grooves 39 can each have a first groove surface 391 and a second groove surface 392. The first groove surface 391 and the second groove surface 392 can each be a reflective surface. For example, the first groove surface 391 and the second groove surface 392 can each be formed by applying a reflective material to two groove walls of the groove 39. In other words, the first groove surface 391 and the second groove surface 392 can each reflect light. When light is incident on the first groove surface 391 or the second groove surface 392, the light can be reflected by the first groove surface 391 or the second groove surface 392. In some embodiments, the first groove surface 391 of one of the grooves 39 can be connected to the second groove surface 392 of an adjacent groove 39. In other words, the plurality of grooves 39 can be arranged in close proximity to each other. In this case, the plurality of grooves 39 can collectively form a sawtooth structure.

[0075] For example, the first groove surface 391 and the second groove surface 392 can form a first included angle a. The first included angle a can be in a range of 60° to 120°. The first groove surface 391 can have a first width D1. The second groove surface 392 can have a second width D2. The first width D1 and the second width D2 can each be greater than or equal to 10 microns. In this way, the first groove surface 391 and the second groove surface 392 can each have a width. On one hand, the width can prevent the mechanical stress from being too large. On the other hand, the width can facilitate the formation of the first groove surface 391 and the second groove surface 392 during the machining of the grooves 39. In other words, the width can facilitate the machining of the grooves 39. It should be noted that the width of the first groove surface 391 can extend in a direction that intersects the width of the second groove surface 392. In addition, the width of the first groove surface 391 and the width of the second groove surface 392 can each extend in a direction that intersects the length of the groove 39.

[0076] For example, the optical folding element 30 can further include a light-absorbing layer (not shown). The light-absorbing layer can be fixed in the groove 39 and cover the first groove surface 391 and / or the second groove surface 392. For example, the light-absorbing layer can be formed by applying a light-absorbing ink to the first groove surface 391 and / or the second groove surface 392 or by applying a light-absorbing film to the first groove surface 391 and / or the second groove surface 392. In this way, when light is incident on the first groove surface 391 or the second groove surface 392, at least part of the energy of the light can be absorbed by the light-absorbing layer. In other words, the light-absorbing layer can reduce the intensity of the light.

[0077] FIG. 10 is a ray transfer diagram of the camera module 100 shown in FIG. 5. In FIG. 10, (a) and (b) are ray transfer diagrams of stray light entering the optical folding element 30 at different angles, respectively.

[0078] As shown in FIG. 5, FIG. 7 and FIG. 10, when a user takes a photo, the light from the external environment can pass through the lens 20 and enter the interior of the optical folding element 30 through the incident surface 30a of the optical folding element 30. The light entering the camera module 100 can include first light and second light. The first light can be valid light in the photo area. The second light can be stray light outside the photo area. After the first light enters the interior of the optical folding element 30 through the incident surface 30a, the first light can pass through multiple reflections between multiple reflection surfaces and finally exit the optical folding element 30 through the exit surface 30b and form an image on the image sensor 50. After the second light enters the interior of the optical folding element 30 through the incident surface 30a, the second light can be reflected by the reflection surface to the bottom surface (i.e., the second surface 32 in this embodiment) of the optical folding element 30 or directly transmitted to the bottom surface of the optical folding element 30. When the second light is transmitted to the first groove surface 391 or the second groove surface 392 of the groove 39, the stray light can be reflected in the direction towards the incident surface 30a under the action of the first groove surface 391 and / or the second groove surface 392 of the groove 39 and finally exit through the incident surface 30a.

[0079] It can be understood that, in this embodiment, the optical folding element 30 is provided with multiple grooves 39 on the bottom surface (i.e., the second surface 32 in this embodiment) of the optical folding element 30, and the groove 39 can have the first groove surface 391 and the second groove surface 392 arranged at an included angle, both of which can be reflection surfaces. In this way, when the stray light is reflected to the second surface 32, the stray light can be reflected by the first groove surface 391 and / or the second groove surface 392 and transmitted in the direction towards the incident surface 30a. That is, the stray light reflected by the first groove surface 391 and / or the second groove surface 392 of the groove 39 will not finally exit through the exit surface 30b and form an image on the image sensor 50, thereby effectively reducing the influence of the stray light on the imaging quality and facilitating improvement of the user's photo-taking experience.

[0080] Secondly, the optical folding element 30 in this embodiment can also include a light-absorbing layer. The light-absorbing layer can be arranged on the first groove surface 391 and / or the second groove surface 392. In this way, when the stray light is reflected to the first groove surface 391 or the second groove surface 392, at least part of the energy of the stray light can be absorbed by the light-absorbing layer, thereby effectively weakening the energy of the stray light and reducing the influence of the stray light on the imaging quality, and facilitating improvement of the user's photo-taking experience.

[0081] In addition, the included angle between the first groove surface 391 and the second groove surface 392 of the groove 39 in the embodiment can be in the range of 60° to 120°. In this way, the included angle between the first groove surface 391 and the second groove surface 392 is appropriate, so that the first groove surface 391 and the second groove surface 392 can better reflect stray light incident on the second surface 32, avoid the stray light from being imaged on the image sensor 50, and help improve the imaging quality and enhance the user experience.

[0082] In other embodiments, referring to FIG. 11 in combination with FIG. 7, FIG. 11 is a structural schematic diagram of the optical folding element 30 shown in FIG. 7 in other embodiments. The light-blocking layer 38 can divide the second surface 32 into a first region 321 and a second region 322. The first region 321 can be disposed closer to the first side 33 than the second region 322. The grooves 39 located in the first region 321 can constitute a first group of grooves 39a. The grooves 39 located in the second region 322 can constitute a second group of grooves 39b. At this time, the first group of grooves 39a and the second group of grooves 39b can be located on opposite sides of the light-blocking layer 38. Exemplarily, the first group of grooves 39a and the second group of grooves 39b can be spaced apart from the light-blocking layer 38. In this way, when stray light is reflected to the second surface 32, part of the stray light can be reflected to the first groove surface 391 or the second groove surface 392 of the groove 39 and reflected in the direction toward the incident surface 30a under the action of the first groove surface 391 and / or the second groove surface 392. Part of the stray light can also be reflected between the first group of grooves 39a and the light-blocking layer 38 or between the second group of grooves 39b and the light-blocking layer 38. This part of the stray light can be reflected by the second surface 32 to the light-blocking layer 38, that is, blocked by the light-blocking layer 38, and also not emitted by the exit surface 30b.

[0083] It should be noted that the spacing distance between the first group of grooves 39a and the light-blocking layer 38 and the distance between the second group of grooves 39b and the light-blocking layer 38 can be determined according to the height of the light-blocking layer 38 and the size parameters of the optical folding element 30.

[0084] The structure of the optical folding element is specifically introduced above, and the shape structure of the groove 39 of the optical folding element 30 will be specifically introduced below in combination with the related drawings.

[0085] FIG. 12 is a partial cross-sectional structural schematic diagram of the optical folding element 30 shown in FIG. 7 along C-C in an embodiment.

[0086] As shown in FIG. 7 and FIG. 12, the recess 39 can be provided with a light-absorbing layer 393. The first groove surface 391 can be connected to the second groove surface 392. The first width D1 of the first groove surface 391 can be equal to the second width D2 of the second groove surface 392. At this time, the cross section of the recess 39 in the X-Z plane can be substantially isosceles triangular. The included angle between the first groove surface 391 and the second surface 32 can be equal to the included angle between the second groove surface 392 and the second surface 32.

[0087] Exemplarily, the first groove surface 391 can be perpendicular to the second groove surface 392. The first included angle a can be 90°. Wherein, the first groove surface 391 and the second groove surface 392 can be completely perpendicular or approximately perpendicular within the range allowed by processing error, for example, when the angle of the first included angle a is between 80° and 100°, it can be considered that the first groove surface 391 and the second groove surface 392 are perpendicular. At this time, the cross section of the recess 39 in the X-Z plane can be substantially isosceles right triangle.

[0088] Exemplarily, the light ray can enter the first groove surface 391 or the second groove surface 392 along a first propagation direction T1. The first propagation direction T1 can intersect the normal direction of the second surface 32. The light ray can pass through the first groove surface 391 or the second groove surface 392 after one reflection, and pass towards the incident surface 30a along a second propagation direction T2 (see (a) and (b) in FIG. 12). The second propagation direction T2 can intersect the first propagation direction T1, or coincide with the first propagation direction T1.

[0089] Exemplarily, the light ray can enter the first groove surface 391 or the second groove surface 392 along a third propagation direction T3. The third propagation direction T3 can intersect the normal direction of the second surface 32. The light ray can pass through the first groove surface 391 and the second groove surface 392 after a total of two reflections, and pass towards the incident surface 30a along a fourth propagation direction T4 (see (c) and (d) in FIG. 12). The fourth propagation direction T4 can be parallel to the third propagation direction T3. Alternatively, the light ray can also enter the first groove surface 391 or the second groove surface 392 along a fifth propagation direction T5. The fifth propagation direction T5 can be parallel to the normal direction of the second surface 32. At this time, the light ray can pass through the first groove surface 391 and the second groove surface 392 after a total of two reflections, and pass towards the first surface 31 along a sixth propagation direction T6 (see (e) in FIG. 12). The sixth propagation direction T6 can be parallel to the fifth propagation direction T5, that is, the sixth propagation direction T6 can be parallel to the normal direction of the second surface 32. In other words, the light ray can pass through the first groove surface 391 and the second groove surface 392 after a total of two reflections, and return to the first surface 31 along the propagation direction of entering the first groove surface 391 or the second groove surface 392, without passing to the exit surface 30b.

[0090] It can be understood that the angle between the first groove surface 391 and the second groove surface 392 of the groove 39 in the embodiment forms a first included angle a, which can be 90°, and the width of the first groove surface 391 can be equal to the width of the second groove surface 392. In this way, the stray light of any angle of incidence on the second surface 32 of the optical folding element 30 can be returned to the first surface 31 by one or two reflections of the first groove surface 391 and / or the second groove surface 392, so that the stray light can be effectively prevented from imaging on the image sensor 50, which is beneficial to reduce the influence of the stray light and improve the imaging quality of the camera module 100.

[0091] In other embodiments, referring to FIG. 13, which is a cross-sectional simplified schematic view of the groove 39 in other embodiments shown in FIG. 12. During the preparation of the groove 39, there is a certain processing and preparation error. For example, the connection between the first groove surface 391 and the second groove surface 392 of the groove 39 can also have a rounded corner. At this time, the height of the triangle in which the first groove surface 391 and the second groove surface 392 are located is H1. The radius of the rounded corner can be less than or equal to 10% of the height H1 of the triangle in which the first groove surface 391 and the second groove surface 392 are located. In this way, the cross section of the groove 39 can be approximately triangular, which can better reflect the stray light incident on the second surface 32 in the direction toward the incident surface 30a, avoid imaging of the stray light, and be beneficial to ensure the imaging quality.

[0092] For example, two adjacent grooves 39 can be spaced apart along the arrangement direction thereof. The spacing distance H2 between the two adjacent grooves 39 can be less than or equal to 10% of the height H1 of the triangle in which the first groove surface 391 and the second groove surface 392 are located. At this time, the two adjacent grooves 39 can still be considered as being arranged closely. For example, the height H1 of the triangle in which the first groove surface 391 and the second groove surface 392 are located can be the distance between the intersection of the first groove surface 391 and the second groove surface 392 and the opening of the groove 39. In this way, the distance between the two adjacent grooves 39 is close, so that the stray light incident on the second surface 32 can be more reflected by the groove surface of the groove 39, thereby reducing the influence of the stray light on the imaging quality and improving the user's shooting experience.

[0093] FIG. 14 is a cross-sectional simplified schematic view of the groove 39 in other embodiments shown in FIG. 12.

[0094] In some embodiments, as shown in FIG. 7, the first included angle a can also be 60°. At this time, the cross section of the groove 39 in the X-Z plane can be substantially an isosceles triangle. As shown in (a), (b), (c) of FIG. 7, when the light ray enters the first groove surface 391 or the second groove surface 392, the light ray can be totally reflected once or more than once on the first groove surface 391 or the second groove surface 392, and is transmitted in the direction towards the first surface 31, so as to avoid the stray light from being imaged on the image sensor 50 (see FIG. 5).

[0095] FIG. 15 is a cross-sectional simplified schematic view of the groove 39 in some other embodiments shown in FIG. 12.

[0096] In some other embodiments, as shown in FIG. 7 and FIG. 15, the first included angle a can also be 120°. At this time, the cross section of the groove 39 in the X-Z plane can be substantially an isosceles triangle. As shown in (a), (b), (c) of FIG. 15, when the light ray enters the first groove surface 391 or the second groove surface 392, the light ray can be totally reflected once or twice on the first groove surface 391 or the second groove surface 392, and is transmitted in the direction towards the first surface 31, so as to avoid the stray light from being imaged on the image sensor 50.

[0097] FIG. 16 is a schematic view of the preparation process of the optical folding element 30 in some embodiments shown in FIG. 7. FIG. 17 is a schematic view of the preparation process of the optical folding element 30 in some embodiments shown in FIG. 7.

[0098] In some embodiments, as shown in FIG. 16, the groove 39 in the optical folding element 30 can be prepared by laser shaping. For example, according to the material of the optical folding element 30, the size of the groove 39 and other parameters, the wavelength, the surface type, the processing depth of the laser and the moving speed of the platform carrying the initial prism can be selected, and the bottom surface (in this embodiment, the second surface 32) of the optical folding element 30 can be engraved by laser to form a plurality of arrayed grooves 39. Then, the groove surface in the groove 39 can be coated with light-absorbing ink to form the light-absorbing layer 393. The light-absorbing layer 393 can completely cover the groove surface of the groove 39.

[0099] In some embodiments, as shown in FIG. 17, the groove 39 of the optical folding element 30 can also be prepared by grinding and polishing (including grinding and polishing) with a grinding wheel. For example, according to the size of the groove 39, a grinding wheel with a suitable surface type can be selected to grind the bottom surface (in this embodiment, the second surface 32) of the optical folding element 30, thereby forming a plurality of arrayed grooves 39. Then, the groove surface in the groove 39 can be coated with light-absorbing ink to form the light-absorbing layer 393.

[0100] It should be noted that the features of the embodiments in the present application can be combined with each other without conflict, and any combination of the features in different embodiments is also within the protection scope of the present application, that is, the above-described multiple embodiments can also be combined as needed.

[0101] It should be noted that all the above-mentioned drawings are exemplary illustrations of the present application, and do not represent the actual size of the product. The size ratio relationship between the components in the drawings is not limited to the actual product of the present application.

[0102] The above is only part of the embodiments of the present application, and the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An optical folding element (30) characterized by, The optical folding element (30) comprises a first surface (31) and a second surface (32) arranged oppositely, the first surface (31) comprises an incident surface (30a) and an exit surface (30b), the optical folding element (30) further comprises a plurality of grooves (39), the openings of the plurality of grooves (39) are formed on the second surface (32), and the groove surfaces of the grooves (39) can reflect light; Wherein, a first light enters the optical folding element (30) from the incident surface (30a), and is emitted from the exit surface (30b) after multiple reflections inside the optical folding element (30), and a second light enters the optical folding element (30) from the incident surface (30a) and is reflected in the direction towards the incident surface (30a) under the action of the groove surfaces of the grooves (39).

2. The optical folding element (30) according to claim 1, characterized in that The incident surface (30a) and the exit surface (30b) are arranged in a first direction (X), and the plurality of grooves (39) are arranged in the first direction (X).

3. The optical folding element (30) according to claim 1, characterized in that The grooves (39) are long strips, and the length extension direction of the grooves (39) is parallel to the width extension direction of the optical folding element (30).

4. The optical folding element (30) according to any one of claims 1 to 3, characterized in that The groove surface of the groove (39) comprises a first groove surface (391) and a second groove surface (392) arranged oppositely, and the first groove surface (391) is arranged at an angle with the second groove surface (392).

5. The optical folding element (30) according to claim 4, characterized in that The first groove surface (391) and the second groove surface (392) form a first included angle (α), and the angle of the first included angle (α) is between 60° and 120°. Alternatively, the angle of the first included angle (α) is between 80° and 100°.

6. The optical folding element (30) according to claim 4, characterized in that The width of the first groove surface (391) is greater than or equal to 10 microns. And / or, the width of the second groove surface (392) is greater than or equal to 10 microns.

7. The optical folding element (30) according to claim 4, characterized in that The width of the first groove surface (391) is equal to the width of the second groove surface (392).

8. The optical folding element (30) according to claim 4, characterized in that The first groove surface (391) is connected to the second groove surface (392). Alternatively, the connection between the first groove surface (391) and the second groove surface (392) forms a rounded corner, and the radius of the rounded corner is less than or equal to 10% of the height (H1) of the triangle in which the first groove surface (391) and the second groove surface (392) are located.

9. The optical folding element (30) according to claim 4, characterized in that The distance between adjacent two grooves (39) is less than or equal to 10% of the height (H1) of the triangle in which the first groove surface (391) and the second groove surface (392) are located.

10. The optical folding element (30) according to any one of claims 1 to 3, characterized in that The optical folding element (30) further comprises an optical absorption layer (393) fixed in the groove (39) and covering at least part of the groove surface of the groove (39).

11. The optical folding element (30) according to any one of claims 1 to 3, characterized in that The optical folding element (30) further comprises a first reflecting surface (371) and a second reflecting surface (372), the first reflecting surface (371) and the second reflecting surface (372) are located between the first surface (31) and the second surface (32), the first reflecting surface (371) and the second reflecting surface (372) are arranged at an angle, and the distance between the first reflecting surface (371) and the second reflecting surface (372) decreases in the direction towards the second surface (32).

12. The optical folding element (30) according to claim 11, characterized in that The optical folding element (30) further comprises a light blocking layer (38), the light blocking layer (38) is located between the first reflecting surface (371) and the second reflecting surface (372), the light blocking layer (38) is fixedly connected to the second surface (32), and is arranged at a distance from the first surface (31), and a light transmission area is formed between the light blocking layer (38) and the first surface (31).

13. A camera module (100), characterized by The camera module (100) comprises a lens (20), an image sensor (50), and the optical folding element (30) according to any one of claims 1 to 12, the lens (20) and the image sensor (50) are located on the side of the optical folding element (30) away from the second surface (32), the lens (20) is arranged opposite to the incident surface (30a), and the image sensor (50) is arranged opposite to the exit surface (30b).

14. An electronic device (1000), characterized by, The camera module (100) comprises an image processor and the camera module (100) according to claim 13, the image processor is in communication connection with the camera module (100), and the image processor is used for acquiring image data from the camera module (100) and processing the image data.

Images